Work supporting tray for heat treating furnaces



Jan. 11, 1944. uc s 2,338,784

WORK SUPPORTING TRAY FOR HEAT TREATING FURNACES Filed Oct. 24, 1941 2 Sheets-Sheet 1 5 HM! il illhHHH NH ll L Ill: Hill: H H El E! H i! i I l6 3 N I? INVENTOR. ALFRED RUCKSTAHL M MM ATTORNEYS 1944- A. RUCKSTAHL 2,33

WORK SUPPORTING TRAY FOR HEAT TREATING FURNACES Filed Oct. 24, 1941 2 Sheets-Sheet 2 'fim jr JLJ IY JF FIG.7.

54 53 FlG.8.

F G .9. I INVENTOR.

ALFRED RUCKSTAHL ATTORNEYS Patented Jan. 11, 1944 WORK SUPPORTING TRAY FOB HEAT TBEATIN G FURNACES Alfred Buckstahl, Dearborn, Mich, minor to liolcroft & Company, Detroit, Micla, a corporation of Michigan Application October 24, 1941, Serial No. 418,305

4 Claims. ('01. 263-47) This invention relates generally to work supporting trays and refers more particularly to those designed for use in heat treating furnaces.

Usually parts to be heat treated are carried on rigid trays that are normally in the form of cast metal grids or plates of suitable size and shape. Such trays are pushed through the furnace on one or more supporting rails or may be carried on chains, driven rolls, or any other suit- 7 able means.

When heated to normal operating temperatures, the trays mentioned lose over 90% of their strength, hence it is necessary to use larger size trays which must be made of stronger sections or must be supported on more than two rails. In the latter case, it is not practical to maintain an alignment so that a tray will always rest on all rails while being pushed or conveyed through the furnace. Therefore. atflrst the tray rests upon two rails, then due to load and heat will sag or bend until it rests on the other rails. This bending or flexing causes breakage and decreases the life of the trays, which are usually made of an alloy containing a high percentage of nickel and chromium and are costly.

Another tray structure used in the past was made of two or more sections hinged or pivotally secured together; however, they were difficult to handle outside the furnace and were expensive to manufacture. For example, when it was desired to lift them to dip and quench the work thereon or to transport or move them about outside the fumace, the hinge or pivotal joints between the sections permitted said sections to move relative to each other and thereby tipped,

tilted or spilled the work thereon. Moreover,

some means had to be provided to stop or limit the pivotal or hinge action between the sections,

- and while the play allowed by suchstops was adequate for the sections when upon the rails in the furnace, it was too much for said sections when lifted outside the furnace. More material was needed to form the stops and this added to the cost of manufacturing such trays.

In the present instance, I have provided a tray structure having two or more separate sections that are normally substantially rigid with each other in edge-to-edge relation so that outside the furnace they may be lifted or moved about like a one-piece structure, but are capable of moving relative to each other when subjected to the heat tions and are capable at another time of flexing to permit the relative movement aforesaid. Actually the tray structure is shallower, less material is employed in the construction thereof, the differential in stresses is less, the cost of manufacture is less, and the structure can be handled and moved about easier and with greater safety than heretofore.

In the accompanying drawings:

Figure 1 is a top plan view of a tray structure embodying my invention and showing portions of the supporting track rails therefor;

Figure 2 is a sectional view taken substantially on the line 2-2 of Figure 1;

Figure 3 is a sectional view taken substantially on the line 3-3 of Figure 1;

Figure 4 is a top plan view of a slightly modifled form of tray structure;

Figure 5 is a sectional view taken substantially on the line 55 of Figure 4;

Figure 6 is a sectional view taken substantially on the line 6-6 of Figure 4;

Figure '7 is a top plan view of another modifled form of tray structure;

Figure 8 is a sectional view taken substantially on the line 8-8 of Figure '7;

Figure 9 is a top plan view of another modified form of tray structure.

Referring now to the drawings, I0, I l and I2, respectively, are the track rails, and I3 isa work supporting tray embodying my invention.

As shown, the center rail H is inverted channel-shaped while the outer rails I0 and i2 are in within a furnace for proper supporting engagement with the track rails therefor. Such structure includes normally straight rods that serve at one time as rigid connectors between the seethe form of I-beams and have upstanding flanges I4 and I5, respectively, at their outer edges for guiding the tray 13. Such rails may be mounted upon any suitable means (not shown) such as the floor of a heat treating furnace.

The tray 13 preferably has two sections it and i1 that are identical in construction and are connected together in edge-to-edge relation by substantially parallel normally straight rods l8 and I9, respectively. Each section is a nickel chrome alloy casting in the form of an elongated grating having substantially parallel sides 20 and 2|, substantially parallel ends 22 and 23, circular portions 24 disposed in transversely and longitudinally extending rows and interconnected by webs 25 and 26, respectively, and transversely extending webs 21 projecting from the sides 2. and' tions 24.

1 length to extend through the two innermost transverse webs 21 of the sections it and I1 and have heads or retaining element 28 at opposite ends thereof. Preferably such heads are'unon the outer sides-of the adiacent wells 21 and may be secured thereto if desired. it and is may be any'suitable size orcross section and.

Y may be made of any'suitable material, but are preferably cylindrical and are formed or nickel chrome alloy sothat normally. i. e., when outside the furnace, they constitute rigid connectors be-' tween the sections and will hold such sections suhstantially'rigidwith each other, but are capable oi flexing when subjected to the heat within; the furnace to permit thesections of the tray to move relative to each other for proper supporting'enga'gement with the track rails H), II and II.

In use, the work (not shown) .to be heat treated is placed upon the tray is and the latter is moved along the rails I I, i I and I! located within the furnace. Thus, heat within the furnace is free to circulate .in the space between the rails beneath the tray and through the grating struc ture of the trayto the work thereon. As a result of the intense heat-within the furnace and the 1 load or weight of the work on the tray sections,

the rods I! and is will flex suillciently to permit said sections to move relative to each other should it be necessary 'for them to do so for the tray sections to have proper supporting engagementwith the rails II. II and I 2. However, before the tray is. inserted into the furnace or after it has been removed therefrom, the rods l8 and I! are free of the heat mentioned and therefore are sufllciently stiff and rigid to hold the sections it and ll of the tray substantiallyrigid with each other and thereby preventobjectionable relative movement when, for example, it is desired to lift or move the tray about for any purpose.

In Figures 4 to c, inclusive, 1 have illustrated a slight modification wherein the sections 30' and ll of the'tray' have alternating projections 32 and II, respectively, arranged in transverse align ment at approximately the center of the tray and are connected by rods 34 and ii that are similar in construction to the rods II and is and extend through lugs 36 projecting inward from opposite sides 31 and 38, respectively, of the sections. In

this instance, the tray i substantially squareshape in plan and the sections and II thereof are gratings having substantially square-shaped rails 80' and 40- -for the tray are I-beams upo which the sections openings. The outer, support 30 and 3| are adapted-to slide, while parallel center rails II and '42 carry therebetween rollers 43 1 that engage .the underside of the transversely aligned alternate projections 32 and 33; respectively, or the tray sections...--'Any suitable means such as theflanges and 45 depending from the underside of the alternate projections 32 and i3 and disposed upon the outer sides Qt the rails ll and 42 may be employed as guides for the jtrayi In Figures 7 and 8, I have illustrated another but subject assayed are similar construction to the rods" ll. As shown, the rods Cl, 0., l1 and II extend trans- 1 'versely-of the sections I, 62, 08 and N and engage aligned holes in longitudinally extendingwebs H thereof, the rod '0 extendslon'gitudinally or the sections BI and II at one side-of the tray and engages aligned holes in lugs" projecting inward from the outer sides of said section's, whil the rod II extends longitudinally the sections l2 and 64 at the opposite side of the tray and engages aligned holes in lugs I3 projecting inward from the outer sides of the sections I! and aligned alternate projections 14;- II, is and II, respectively, of the tray sections which are similar to the alternate projections 32 and ll in Figure 4 and may be supported in alike manner.

In each of the forms shown, the underlying principle is the same, namely, the provision of sections that are normally substantially rigid with v each otherin edge-to-edge relation so that 'outside the furnace they may be lifted or moved about like a one-piece structure, but are capable when subjected to heat within a furnace of moving relative to each other for proper supporting engagement with the track rails or their equivalents. In each instancathe rods normal- 1y .serve as rigid connectors between the sec-- tions but are capable of flexing to permitthe relative movement mentioned. Likewise, in each instance, the rods serve as stifieners or reinforcing members forthe. respective sections. Thus,

the desired results" are accomplished with the minimum number of parts.

- What I claim as my invention is;

v 1. A- work supporting tray of the class 'de-, scribed comprising-two separate rigid section arranged substantially end to end'in substantially a common horizontal plane, said sections being provided adjacent opposite side edges thereof near the line of juncture betweensaid sections with longitudinally spaced transversely xtending rigid 1'- portions, and rigid rods extending across the line of junctur between said, sections ande'x tending longitudinally of said sections adjacent opposite side edges thereof, said rods'extending through and held against displacement from'the transversely extending rigid portions of said sections and constituting the sole connecting means between said sections, said rods normally resisting relative hinge action between said section's axe thereof at the line of juncture between the sections with longitudinally sp modification-wherein parallel rods II and 5] sim-- ilar in construction to the rodsi8 and I! extend transversely of the tray and engage transversely aligned holes in oppositely extending alternately upstanding guide 8' and 64, respectively, connected together by six rods. as, u, u, u, u and n. spectively, that two sections to pernit relative hinge'action betw'eensaid sectiona. 1

2. A work supportingfi'trayof the class described comprising two separate rigid sections arranged substantially end to. end in substantially a common'horizontal plane, said sections being provided near the line of juncture between; saijd ce'd transversely extending rigid portions, an

placement from the transversely extending rigid j portions .of 'said section and constituting the I sole'connectlng means between said sections, said elongated rigid; member normally resisting relative hinge action betweensaid sections but sub.-

ject to bending stress transverse of the axes thereof at thelinef of juncture between the two sections to permit relative hingev action between saidsectionsi.

At the center of the tray are to bending stresstransverseioi'tm I elongated j.rigid members: extending across the line of'iuncture between said sections and: extending longitud'ie nally of said section's, said elongated rigid'membersextending through and held against dis- 3. A work supporting tray of the class described comprising two separate rigid sections arranged substantially end to end in substantially a common horizontal plane, said sections being provided with spaced transversely extending rigid portions, and elongated rigid members extending between and longitudinally of said sections, said elongated rigid members extendin through and held against displacement from the transversely extending rigid portions of said sections and constituting the sole connecting means between said sections, said elongated rigid members normally resisting relative hinge action between said sections but subject to bendin stress transverse of the axes thereot at the line of juncture between the two sections to permit relative hinge action between said sections.

4. A work supporting tray of the class described comprising two separate rigid sections arranged substantially edge to edge in substantially a common horizontal plane, said sections having longitudinally spaced transversely extending rigid portions arranged in laterally spaced substantially parallel rows, and rigid rods extending across the line of juncturebetween said sections and extending longitudinally of said rows 01 transversely extending rigid portions, said rods extending through and held against displacement from the transversely extending rigid portions of said sections and constituting the sole connecting means between said sections, said rods I normally resisting relative hinge action between said sections but subject to bending stress trans- I verse of the axes thereof at the line of juncture between the two sections to permit relative hinge action between said sections.

ALFRED RUCKSTAHL. 

